The Global Positioning System (GPS) is a satellite-based navigation system made up of a network of satellites in orbit. GPS satellites circle the earth in a precise orbit and transmit signal information to earth. GPS receivers take the signal information and use triangulation to calculate the receiver's location. The GPS receiver can compare the time a signal was transmitted by a satellite with the time it was received. The time difference tells the GPS receiver how far away the satellite is. With distance measured from several satellites, the receiver can determine the receiver's position and display it. Once the receiver's position has been determined, a GPS device can calculate other information, such as speed, bearing, track, trip distance, distance to destination, sunrise and sunset time and more.